1. Field of the Invention
The present invention relates generally to a jig for assembling a rotor and, more particularly, to a jig for assembling a rotor, which is capable of preventing a rotor casing from being deformed when a rotating shaft is press-fitted into the rotor casing.
2. Description of the Related Art
A rotor is a part that is used in a spindle motor installed in a hard disk drive or a CD drive. The rotor includes a rotor casing and a rotating shaft, which supports the rotor casing. A rubber ring is mounted to the rotor casing to prevent the slippage of a recording medium.
The rotor of the spindle motor is assembled such that the rotating shaft is press-fitted into the rotor casing using a jig to which a pressing force is applied. One example of the jig for assembling the rotor is schematically shown in FIGS. 3 and 4.
As shown in FIGS. 3 and 4, a conventional rotor assembly jig 200 includes an upper jig part 210, a lower jig part 220, and a guide jig part 240. A rotor 260 includes a rotor casing 261, a rubber ring 262, and a rotating shaft 263.
The upper jig part 210 functions to apply pressing force to the rotating shaft 263, and includes a plate-shaped body 211 and a pressure protrusion 212 for pressing the rotating shaft 263. At least part of the pressure protrusion 212 is inserted into the guide jig part 240 and directly presses the rotating shaft 263.
The lower jig part 220 functions to support the rotor casing 261, and includes a plate-shaped body 221 and a cavity 222 for receiving the rotor casing 261. The bottom of the cavity 222 is stepped to correspond to the rotor casing 261. A holder seat 223 is formed in the body 221 for insertion of a holder 264 of the rotor casing 261 into the holder seat 223.
The guide jig part 240 functions to guide the pressed rotating shaft 263 into the rotor casing 261, and has a through hole 241 which is open toward the holder 264 of the rotor casing 261.
As shown in FIG. 4, the rotating shaft 263 is press-fitted into the rotor casing 261 by pressing force.
First, the rotor casing 261 is seated in the cavity 222 of the lower jig part 220, and the guide jig part 240 is placed above the rotor casing 261.
Next, the rotating shaft 263 is inserted into the through hole 241 to be guided to the holder 264, and is press-fitted into the holder 264 by the pressure protrusion 212 of the upper jig part 210. At this time, the upper jig part 210 presses the rotating shaft 263 in the direction shown by arrow A due to the pressing force. When the lower surface of the upper jig part 210 meets the upper surface of the lower jig part 220, the insertion of the rotating shaft 263 is completed.
However, since a surface 265 of the rotor casing 261 having no rubber ring is not supported by the lower jig part 220, the rotor casing 261 is bent in the direction A where pressing force is applied, and is thus deformed when the rotating shaft 263 is press-fitted into the rotor casing 261.